Adjustable metallic thermostat



Sept, 6, 1Q3& P. B. PARKS ADJUSTABLE METALLIC THERMOSTAT Filed Sept. 20, 1937 2 Sheets-Sheet-l Imfeh'fiir: FM ,5 .Hzny Q Sept. 6, 1938. P. B. PARKS I 2,129,477 ADJUSTABFE METALLIC THERMOSTAT Filed Sept. 20, 1937 2 Sheets-Sheet 2 4 2 w M'I WI I llllllll I T018 T11257 3221/ b Par/Z5"- r" fixing??? PatentedSept. e, 1938 2,129,477 ADJfiSTABLE rm'mmc THEBMOSTAT Paul B. Parks, Oak Park, 111., assignor to Vapor Oar Heating Company, Inc., poration of New York OhicagoJILacor- Application September 20,1931, Serial Nb. 164,179

12 Claims. (crane-1:21

This invention relates to certain new and useful improvements in thermostats or-simllar controlling instruments, especially thermostats of the bi-metallic type having a portion movable in response to atmospheric temperature changes to I which the bi-metallic member is exposed so as to operate some controlling mechanism, usually by ,making'or breaking electric circuits.

According to the present invention, means isprovided for conveniently adjusting the operation of the control instrument, for example selecting the temperature or temperatures I at which the instrument will function. A localized portion of the thermostatic member, or more conveniently a second thermostatic member fixed at one end and adiustably connected at the other end with the relatively fixed portion of the main thermostat, is confined within a casing along with an auxiliary heater so that the heat output of this be influenced by air currents to which the main heater will be locally applied to the second ther- I mostat only, and this second thermostat will not w thermostat responds. By adjusting the auxiliary.

ing coil is positioned around the second thermostatic bar (or some other type of electric heating element is intimately associated'therewith) and both the bar and electric heater are enclosed in an insulating casing which is entirely closed except-for a passage for the movable member by which adjustable connection is made with the anchored or relatively flxed portion of the main thermostat. In this manner the auxiliary heat is localized and applied only to the auxiliary or adjusting thermostatic member which is shielded from air currents, whereas the main exposed thermostatic member is shielded as far as possible from the auxiliary heat so as to respond only to atmospheric temperature changes.

The principal object of this invention is to provide. an improved controlling instrument such as briefly described hereinabove and disclosed more in detail in the specifications which follow.-

56 Another object is to provide improved means for localizing as far possible the application at which the thermostats will function.

Other objects and advantages of this invention will be more apparent from the following detailed description of one approved form of 'of auxiliary heat for adjusting the temperature thermostat constructed and operating according to the principles of this invention.

In the accompanying drawingsr Fig. 1 is a side elevation of the instrument, the base and the outer covering shi ld being shown in vertical section. I v

Fig. 2 is a plan view with the outer cover removed and the insulating casing for the auxiliary thermostat and heater being shown in section substantially on the line 2-2 of Fig. 1.

.Fig. 3 is a vertical section taken substantially on the lineI-Iof Fig. 2.

Fig. 4 is a wiring diagram. v

The thermostat comprises the hollow metallic base member I, open at the back, in which the base plate 0! insulating material 2 is secured byscrews 3. The operating parts are mounted on the irontface of plate 2, and the electrical connections are made in the usual manner at the back of plate I. The operating mechanism is enclosed by a dished metallic cover or shield 4 provided with a flange or rim which flts over a portion oi. base I' and may be removably secured thereto inany desired manner. Cover 4 is provided with slots or openings 8 and I in its upper and lower ends, and also preferably with openings I in the sides so that a free circulation of air is permitted through the cover or casing so that the main thermostatic member may respond quickly to room temperatures.

The main thermostatic member 9 is in the form of a bi-metallic bar having one end III fixed at H on an anchoring member I! pivotally mounted on a pin l3 extending outwardly from base plate 2. The bar 9 is bent or looped so as to extend practically aroundthe inner insulating casing l4 (hereinafter described in detail) and -ly fixed they are preferably mounted on the inner ends of screws IIv and 2| respectively 1 mounted in the flxed members 22 and I! so that the positions of the so-called flxed" contacts may be adjusted. It will be understood that as the temperature of the air to which bar Iv is exposed rises or falls, this bar will flex or bend in one direction or the other. For example, it the temperature rises to a predetermined temperature the bar may fiex so as to bring movable contact ll into engagement with fixed contact i8, and conversely if the temperature falls sufiiciently contact II will be brought into engagement with contact it. It will be understood that circuit wires (hereinafter referred to) connect with suitable binding posts on the back oi base 2, these wires leading from the fixed contacts I8, I! and from the relatively fixed end portion of bar 9 respectively.

The end portion ll of ,the thermostatic bar I may be considered as fixed as far as the movements of this bar in respect to atmospheric temperature changes is concerned, but for the purpose of adjusting thetemperatures at which the thermostat will function the bar I is swung bodily in one direction or the other by moving the pivoted anchorage I! to which the relatively fixed .end of bar I is secured.

The improved adjusting means comprises a second thermostatic bar 23 having its lower end fixed at 24 to a block 2| projecting from the base plate, and the upper free end portion 28 or this thermostatic bar is connected with an adjustin screw 21 threaded through a block 28 connected with anchoring member It. It will be apparent that as the auxiliary thermostatic bar 23 fiexes in one direction or the other it will, through screw it, move the anchorage l2 and thereby bodily adjust the position 0! the main thermostat I. the head II of screw 21 is conveniently positioned so that a permanent or factory adjustment may be made by turning the screw 11. As tar as the automatic operation is concerned the tree end ii of auxiliary thermostat 23 may be considered as fixedly secured with the relatively fixed end ll of main thermostat I, and as a matter of fact these two thermostats'may be considered as parts oi the same thermostatic means, or might be parts of the same thermostatic bar.

An electric heating element is intimately associated with the thermostat 28. this heating element being worth! in the form 0! a coil ll wrapped around the thermostatic bar and having its terminals connected respectively to the screws II and 8! which extend throughbase plate I so thattheconnectionsiortheenergizingcircuit may be conveniently made at the back or the The thermostat 28 and heater SI are confined withinthechambertttormedininsulatingcasing llhereinabovereierredtor'ihiscasingll maybemetallimbutispreierably formed of some .berilpmjectingiorwardlyiromhaseplatet Referringnowtothewiringdiagramshownin Hg. 4, twirss "and" areshown leading to fixed contacts II and II respectively,

th whereas a third wire 40 leads to the thermostatic bar I and thence to the movable contacts it and I1. Assuming that the thermostatic bar 9 is so constructed as to swing to the right at its upper end when heated, at a certain predetermined maximum temperature the contacts 18 and It will be en aged to complete a circuit between wires SI and Ill and we may assume that through certain appropriate control mechanism this circuit will cause a cooling system to be thrown into operation or a heating system to be thrown out of operation. Conversely, when the temperature at thermostat l is lowered so that contacts i1 and I9 engage a circuit will be completed through wires 3! and ll to cut oil the cooling mechanism or start the heating mechanism. Alternatively, the circuit connection to one 0! the contacts (for example contact I!) might be omitted and only the contacts I. and ll be used to make or break the circuit between wires 18 and M thus stopping or starting the controlled mechanism.

The heating circuit for energizing the auxiliary heater Ill comprises the wire ll leading from one minal oi. heater ll, and wire 46 leading back to the source of current 42. It will ncw'be seen that as rheostat contact 43 is adjusted, the strength oi the current flowing through coil III will be varied and thereby the heat output adjusted to determine the extent to which thermostat II will be flexed or bowed in one direction or the other th'ereby moving the pivoted anchorage I! to bodily adjust the position of main thermostat 9 for any given atmospheric temperature. In this manner the temperatures at which contact will be established between either of the pairs of contacts ll-il or ll-il may be ad justed at any time by simply adjusting the strength of the energizing current for auxiliary heater Ill.

The insulating case it tends to confine the heat output of this auxiliary heater II to the secondary thermostat 23 while at the same time shielding this adjusting thermostat from the varying air currents which fiow through the outer casing 4. In this manner the main thermostat i is made, as far as possible, responsive only to changes in temperature in the atmosphere or the room or other space in which the thermostat is located,- whereas auxiliary adjusting thermostat it is responsive only to the auxiliary, heafiiur nished by electric heater ll. Preierahly,- I netic detents in the form oi adjustably positioned permanent magnets 41 and It are podtioned adjacent opposite sides of the movable end portion 0! thermostaticv bar I. For example. magnet 41 is so positioned thatwhen contacts I! and are engaged the thermostatic bar is brought closely-enough to the poles of magnet lltobestrongiyattracte'dtherebysothatthe contacts II and II. will be held in engagement until a temperature change-applied to bar 0 exerts sufiicient tome-on this bar in'an opposite direction to break the magnetic attraction and snap apart the contacts II and II. This prevents chattering at the contacts and excessive making and breaking oi the control circuits.

This same type 0! adjusting mechanism could beapplied inasimilarmannertoothertypesoi fiantroiling instruments, for example a humido- As has already been noted. the connecting means here shown by way of example between the two thermostatic members 23 and I. said connecting means comprising screw 21, block 28, and

anchoring member l2, may take a variety of -forms and is principally for the purpose of providing means for a permanent adjustment between these two members (usually an adjustment made at the factory). omitted and the two thermostatic members fixedly connected or formed as a unit, as far as the broader principles of the invention are concerned.

I claim: 1. A controlling instrument comprising a control member having an operating portion movable in relation to a relatively fixed portion in re-' sponse to predetermined changes in atmospheric conditions, a bi-metallic thermostat having a portion movable in response to temperature changes,

means connectingjzhe movable portion of the thermostat withthe relatively fixed portion of the control member, a heat localizing casing enclosing the thermostat, a heater within the easing and intimately associated with the thermostat, and means foreadjustablycontrolling the heat output of the heater.

2. A controlling instrument comprising a control member having an operating portion movable in relation to a relatively fixed portion in response to predeterminedchanges in atmospheric conditlons, a bi-metallic thermostat having a portion movable in response to temperature changes, means adjustably connecting the movable portion of the thermostat with the relatively fixed portion of the control member, a heat localizing casing enclosing the thermostat, a heater within the casing and intimately associated with the thermostat, and means for adjustably controlling the heat output of the heater.

3. A controlling instrument comprising a control member having an operating portion movable in relation to a relatively fixed portion in response to predetermined changes in atmospheric conditions, a thermostat having a portion movable in response to temperature changes, a movable anchorage for the relatively fixed portion 01' the control member, means adiustably connecting the movable portion 01' the thermostat with the anchorage to move the same and thereby adjust the operation of the control member, a heat localizing casing enclosing the thermostat, a heater within the casing and intimately, associ-. ated with the thermostat, and means for adjustably controlling the heat output of the heater.

4. A controlling instrument comprising a control member having an operating portion movable in relation to a relatively fixed portion in response to predetermined changes in atmospheric conditions, a thermostat having a portion movable in response to temperature changes, a movable anchorage for the relatively fixed portion of the control member, means adjustably connecting the movable portion of the thermostat with the anchorage to move the same andthere- 1 by adjust the operation of the control member,

All of this might be tively fixed portion of the control member, a heat localizing casing enclosing the thermostat, an

electric heating element intimately associated with the thermostat, an energizing circuit for the heating element, and means for adjustably controlling the current in the energizing circuit.

6. A thermostat comprising a bi-metallic bar having an operating portion movable with respect to a relatively fixed portion in response to temperature changes of the atmosphere to which the bar is exposed, a movable anchorage for the relatively fixed portion of the bar, a second bi.- metallic bar fixed at one end and secured at the other movable end to the movable anchorage, an electric heating element intimately associated with the second bi-metallic bar, an ,energizing circuit for the heating element, means for adjusting the current in this circuit, and an insulating casing confining the second bi-metallic bar and the heating element to restrict the effect of the heating element to the second bar and protect the second bar from air currents.

7. A thermostat comprising a bi-metallic bar having an operating portion movable with respect to a relatively fixed portion in response to temperature changes of the atmosphere to which the bar is exposed, a movable anchorage tor the relatively fixed portion of the bar, a second bi-metallic bar fixed at one end and adjustably secured at the other movable end to the movable anchorage, an electric heating element intimately associated with the second bi-metallic bar, an energizing circuit for the heating element, means for adof the heating element to the second bar and with the thermostat, an energizing circuit for the heating element, and means for adjustably controlling the current in the energizing,

5. A controlling i 'trument comprising a control member having a operating portion movable in relation to a relatively fixed portion in response to predetermined changes in atmospheric conditions, a bi-metallic thermostat having a portionmovable in response to temperature changes, means adjustably connecting the movable portion of the thermostat with the relaprotect the second bar from air currents.

8 A thermostat comprising a bi-metalic bar having an operating portion movable with respect to a relatively fixed portion in response to temperature changes of the atmosphere to which the [bar is exposed, a pivoted anchoring member on which the relatively fixed portion of the bar is mounted, a second bi-metallic bar fixed at one end, an adjusting member connecting the movable end of the second bar with the pivoted anchoring member, an electric heating element intimately assOciated With the second bar, an energizing. circuit for the heating element, means for adjusting the current in this circuit, and an insulating casing confining the second bar and heating element to restrict the effect of the heating element to the second bar.

9. A thermostat comprising a bi-metallic bar, a movable anchoring member to which one end of the bar is secured, a pair of electric contacts one oi. which is relatively fixed and the other carried by the movable end of the bar so that a circuit through the contacts will be made and broken in response to atmospheric temperature changes to whichthe bar is exposed, a second thermostatic bar fixed at one end, anadjustable connection between the movable end of this bar and the anchoring means, a casing enclosing the second bar, a heater within the casing and intimately associated with the second thermostat to locally apply heat thereto and means for adjusting the through the contacts will be made and broken 13/75 response to atmospheric temperature changes to which the bar is exposed, a second thermostatic bar fixed at one end, an adjustable connection between the movable end oi this, bar and the anchoring means, a casing enclosing the second bar, a heater within the-casing and intimately associated with the second thermostat to locally apply heat thereto, and means for adjusting the heat output of the heater.

ii. A thermostat comprising a bi-metaliic bar. a movable anchoring member to which one end of the bar is secured, a pair of electric contacts one oi which is relatively fixed and the other carried by the movable end of the bar so that a circuit through the contacts will .be made and broken in response to atmospheric temperature changes .to which the bar is exposed, a second thermostatic bar fixed at one end, an adjustable 1y associated with the second bar, an energizing circuitfor this heater, and means for adjusting the energizing circuit.

12. A thermostat comprising a bi-metaiiic bar, a movable anchoring member to which one end oi! the bar is secured, a pair of electric contacts one of which is relatively fixed and the other carried by the movable end of the bar so that a circuit through the contacts will be made and broken in response to atmospherictemperature changes to which the barn exposed, a magnetic detent positioned to attract the bar and yieldingly hold the contacts in engagement, a second thermostatic bar fixed at one end, an adjustable connection between the movable end of this bar and the anchoring means, a casing enclosing the second bar, a heater within the casing and intimately associated with" the second thermostat to locally apply heat thereto, and means for adjusting the heat output of the heater.

PAUL B. PARKS. 

